Adjustable spring sash-balance.



A s. H. LAW. I ADJUSTABLE SPRING SASH BALANCE.

APPLICATION P ILED' F313, 1906.

5 .4 I H v WITNESSES? My 7 INVENTOH PATENTED JULY 17, 1906.

O M QM- V UNITED STATES PATENT OFFICE.

SAMUEL H. LAW, OF NEW YORK, N. Y., ASSIGNOR OF ONE-HALF TO CHARLES M. THOMPSON, OF BROOKLYN, NEW YORK.

ADJUSTABLE SPRING SASH-BALANCE.

Specification of Letters Patent.

Patented July 17, 1906.

Application filed February 3. 1906. Serial No. 299,267.

To aZZ whom it may concern.-

Be it known that I, SAMUEL H. LAW, a citizen of the United States, residing at the borough of Brooklyn, city of New York, county of Kings, and State of'New York, have invented certain new and useful Improvements in Adjustable Spring Sash-Balances, of which the following is a specification.

My invention relates to sash-balances of the classwherein a spring-controlled drum is used having a flexible connection to the windowfrarhe, and more articularly it has relation to such a sash-ba ance provided with means whereby the tension or pull of the spring may be regulated.

A sash-balance of the spring-controlled variety in order to be of commercial value must be.compact, relatively narrow, and with no portions projecting beyond the general surface of the sides plates. In view of this fact my invention conforms in its general lines tda form of spring sash-balance already on i i the market and which because of its comp actness and simplicity has met with the argest acceptance among builders.

The object of my invention is to provide a spring sash-balance of great compactness in which the spring may be tensioned without the need of disassembling the casing and without the removal of the spring therefrom, thus making one balance capable of tension adjustment, so that it will suit for a large va riety of window-weights and do away with the necessity of having several different strengths of springs, a further object in this connection being to rovide means whereby the spring may be he 01 set at any desired tension without any chance of being-released by a change in the position of the balance or through ar or concussion. Further, my invention contemplates a casing for the balance so formed as to be readily disassembled.

The invention consists in the combination of'parts and the details of construction set forth in the claims.

I have illustrated my invention in the accompanying drawings, wherein- Figure 1 is a side view of my sash-balance, the side plate being broken away to show the internal construction. Fig. 2 is a front view. Fig. 3 is a cross-section of Fig. 1 on the line a: no.

In the drawings, where like reference-numerals designate like parts, 2 designates one of the side plates, having a rounded rear edge 2 and astraight front edge at right angles to the top and bottom of the plate. Projecting laterally from the front edge of the side plate is the front plate 3. This is slotted, as at 3, for the passage of the metal tape or other flexible connection 8 and extends beyond the body of the casing to form the usual flanges, whereby the casing may be attached to a window-frame by the screw 3". Projecting laterallyfrom the top and bottom edges of the plates are the top and bottom flanges 4 4. This side plate 2, the front plate 3, and the flanges 4 4 are usually cast in one piece. It is to be noted that the front plate 3 has no overhang along its inside face at 3".

The side plate 2 forms what maybe termed the base-plate of the casing, on which the drum turns and in which sets the other side plate 5. This plate is of the same general shape as the plate 2, but slightly smaller, so as to fit under the top and bottom flange 4 4.

At the upper and lower corners of its front end the plate has laterally-projecting flanges 5 5, which fit against the inside face of the front plate 3. Screw-threaded holes through the front plate and these flanges 5 provide for the reception of screws 5, which hold this side plate 5 securely in place against the front plate 3.

The spring and the metal tape or similar connection are respectively mounted inside and outside of a barrel or drum 6, which is slotted, as at 6, to receive and hold the turned-over end of the spring 7 and slotted at 6 for the attachment of the band or tape 8, which is wound around the stud 6', formed between said slots. The drum 6 is provided with a side web or disk 6, which as an opening at its center for the passage of the arbor 9. Surrounding this opening is an annular flange 6", whose end bears against the side plate 2, thus preventing the frictional contact between the side plate and the drum-disk. It is to be understood that the drum turns freely on the arbor 9, except asit is controlled by the spring, and that this arbor is capable ofturning on the bearings formed in the side plates 2 and 5. The arbor at its ends is shouldered, as at 9", where it enters the bearings in the side plates and is slotted axially, as at 9, for engagement with the s ring 7, as shown particularly in Fig. 1.

t the end of the arbor adjacent to the plate 5 is a screw-hole 9', which enters the shoulder 9 and extends axially along the said arbor, but at a point distant from its center. The opening of this screw-hole registers with an opening in the said plate 5. Through this opening passes the set-screw 10, which enters the screw-hole 9" when the passage and the hole through the plate 5 register. The end of the arbor 9 is slotted or nicked, as at 9 like a screw-head, for the reception of a blade of a screw-driver or other instrument. The tape or band 8, which is attached to the sash, is wound around the drum 7 and then passes out through the slot 3 in the faceplate 3. At its end it carries the usual attaching-ring 8.

The operation of my invention as far as balancing the weight of a sash is concerned is the sameas the sash-balance heretofore referred to; but the difference lies in the turning operation. To tighten the spring, all that is necessary is to take out the screw-pin 10, which allows the arbor 9 to rotate and the spring to run down. The spring may be then tightened to any requisite amount by the insertion and turning of a screwdriver or other like tool into the slot 9*, the band 8 being of course held by its ring 8 coming against the edges of the slot 3. When the spring is sufiiciently tightened, the arbor is turned until its screw-hole 9 registers with the screw-hole in the plate-5, when the screwpin 10 is inserted.

In assembling the parts, as before explained, the arbor is inserted into the drum,

the spring and band attached, and the drum' is placed in position on the base-plate 2. Then without tensioning the spring the plate 5 is placed thereon and the screws 5 5 inserted, drawing the plates together and making a close and tight fit. At any time after that the spring may be tensioned to the proper degree.

The advantages of my invention are as follows: There being no need of tensioning the spring before assembling, it may be assembled more expeditiously, and less care has to be taken in putting the parts together. The springs not needing to be tensioned before being inserted may be left slack while in stock, thus adding to the life of the spring. The same size spring, casing, &c., may be used for sashes varying widely in length, and the balance may be accurately adjusted for each weight of sash. The screw-pin having positive engagement with the arbor, there is no chance of its being accidentally thrown out of place.

Having described my invention, what I claim is 1. A sash-balance having side plates, a rotatable arbor supported in the said side plates, a drum rotatable on the arbor, a flexible sash connection wound upon said drum, a coiled spring attached at one end to the arbor and at the other end to the drum, means on the arbor whereby it may be rotated, and a screw-threaded pin engaging with said arbor to prevent its rotation under the tension of the spring.

2. A sash-balance having a front plate and two side lates, a drum rotatable between the side p ates, a flexible sash connection attached to the drum to be wound thereon, a coiled spring attached at one end to the interior of the drum, a freely rotatable central arbor on which the drum is mounted to revolve and to which the said spring is at tached, said arbor having bearing in but not rojecting beyond the said side plates, and having 'a socket therein for the reception of an engaging pin, means in the end of the arbor whereby it may be engaged by a turning device and a removable pin inserted through the side plate and engaging said socket to prevent the rotation of said arbor, the head of said pin not projecting beyond the outer surface of the said side plate.

3. A sash-balance having side plates, a drum rotatable between the side plates,,a flexible sash connection attached to the drum and wound thereon, 'a coiled spring located within the drum and attached at one end thereto, a freely rotatable arbor supported in the side plates on which the drum is adapted to revolve'and to which the other end of said spring is attached, a shoulder formed on one end of said arbor, -a bearing projecting beyond the shoulder and into the side plate but not beyond the outer face of the same, the-end of said arbor :having means whereby the arbor may be engaged by a turningdevice, and the said shoulder having a screw-threaded socket extending axially thereof for the reception of :an engaging pin, and a pin inserted through an opening in the side plate and engaging with said socket to prevent the rotation of said arbor, the head 1 name to this specification, in the presence of two subscribing witnesses, this 1st day of February, 1906.

SAMUEL H. LAW.

Witnesses:

JonN J. PREW, CnAs. M. THOMPSON.

IIO

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